The art has developed systems for aircraft navigation and targeting purposes, particularly forward looking infrared (FLIR) line of sight systems. U.S. Pat. No. 5,049,740 discloses a system for obtaining images of two fields of view of one or two scenes with a radiation sensor by the use of a single detector and common signal processing circuitry. Said patent describes a field of view sensor providing a narrow view and a wide view by two independent telescopes, which are combined by use of a field of view switch comprising a chopper wheel or an optical switch in synchronized operation with a mirror scanner.
U.S. Pat. No. 5,418,364 discloses a FLIR system for providing both navigation and pilotage functions for which a wide field of view is provided, and a target acquisition or tracking/targeting function, for which a narrow field of view is provided. The wide field of view permits implementation of a pilotage function while the narrow, optionally magnified field of view, implements a targeting function. Both lines of sight are coupled in a single IR detector and two separate FLIR video image signals are generated using a single common processor, one for pilotage and one for targeting.
It is seen that the art provides systems for assisting an aircraft pilot in directing the aircraft and in finding and tracking a target. However, no matter what the width is of the wider of the two fields-of-view, it has a limited angular span and the presence of a narrow field of view, while useful for targeting, does not contribute to the inspection and analysis of the geographical area over which the aircraft flies. The two telescopes that are provided in said prior art have different functions and provide different information and do not complement one another.
It would therefore be desirable to provide a system that would permit acquiring and showing a complete panoramic picture of a relevant geographical area. It would also be desirable if such a system, which could provide discovery, alarming, and location of threats from any direction, could provide such a panoramic view by use of a singe detector. A singe detector system would have many advantages including reduced cost, volume, and weight, over multi detectors system. Examples of applications in which the usefulness of such a system is readily apparent are found in military operations. Typical threats that could be detected and their paths located include enemy missiles, rockets, and bullets, which can come from any direction. Artillery barrages and flight missions could be guided and followed by a system providing such a panoramic view, from a headquarters or forward station on the ground, from which instructions could be transmitted to the artillery unit on the ground or to an aircraft pilot in the air. As another example, the system of the invention can be mounted on an aircraft and could be directly used by the pilot in performing his mission.
It is therefore a purpose of this invention to provide such a system and to provide it by means of an optical system the components of which are known in the art and can be easily acquired, assembled, coordinated and controlled by persons expert in the optical art.
It is another purpose of this invention to provide a system that provides such panoramic views with a single detector.
Other purposes and advantages of the invention will appear as the description proceeds.